In an outboard motor provided with an internal combustion engine housed in an engine room formed by an engine cover, there is known a structure in which an opening portion used to take in combustion air is provided behind the engine cover (see, for example, Patent Documents 1 and 2). In such an outboard motor, the air taken into the engine cover is fed into the engine room. Then, the air is delivered to the combustion chamber after flowing through a space near the engine housed in the engine room.